The Laboratory Core will provide reagents, testing, and in-house validation of the prototype diagnostic tests produced by the three projects. It will be the clearinghouse for obtaining, culturing and distributing Category B enteric parasites and bacteria to Projects 1-3. The core will provide methodology for DNA purification from stool and standard stool bacterial and parasite cultures. Distribution of prototype antigen capture and real-time PCR assays will be via the lab core.